In a new post to his site, Pádraic Brady poses a question about the HHVM project from Facebook - is it going to "be the coffin" that will replace the Zend Engine in PHP completely and change the way we know it?

With HHVM 3.0 now released, it’s probably time to start talking about HHVM and the new Hack Language. It’s becoming hard to ignore some of the fantastical notions spreading on the grapevine about HHVM. There is talk of significant performance improvements, a multitude of new features courtesy of Hack, that PHP Internals is actually now outnumbered by HHVM contributors. There is even treasonous talk of PHP’s Zend Engine being put out to pasture.

He talks about how it was inevitable, really, that there'd be another implementation come up through the ranks (much like the variations of Ruby). He also mentions some other, less popular options in replacing the main implementation (Zephir, HippyVM, etc). He then poses an interesting question - "what is PHP?" He talks about language specifications, the PHP internals group and the delay that sometimes happens introducing new language features into the core (some of which HHVM already has).

PHP, as we know it, is starting to smell. It has gone from being the only PHP in town, to being the slowest, with the least number of features, and the one that’s subject to dysfunctional governance. The new PHP is called Hack, a new language with only the briefest of documentation since you can learn the other 99.9% of this language over on the PHP manual.